Washing appliance

ABSTRACT

A washing appliance ( 2 ) is provided which is comprised of a dedicated reservoir ( 6 ) for the washing appliance ( 2 ), the reservoir ( 16 ) having an inlet ( 12 ) to allow inflow of water and an outlet ( 17 ) to enable outflow of water, and at least one heat exchange means ( 10 ) characterised in that at least one heat exchange means ( 10 ) is adapted and configured to transfer ambient energy outside the reservoir ( 6 ) into the reservoir ( 6 ).

The present invention relates to a washing appliance and, in particular washing appliances which use heated water.

The present invention aims to minimise the energy input from direct paid for energy sources for washing appliances, and in particular laundry appliances. The present invention is equally applicable, however, to other washing appliances, for example, dishwashers.

In known washing appliances a method or sequence of operation for a wash cycle is as follows:

1 the appliance takes in water (the washing water) from the water supply to which it is connected;

2 the washing water is heated to a predetermined temperature by, for example, electrical heating elements;

3 the items to be washed are washed and the washing water drained away;

4 the appliance takes in more water (the rinse water) and.

5 the items to be washed are rinsed and the rinse water drained away.

Usually steps 4 and 5 are repeated. Steps 1 to 3 may be repeated if a pre wash cycle is included in a particular washing cycle.

It is known to, for example as disclosed in GB2124356A (Busch), JP2002078661A (Zojirushi), and JP2000354580A (Tanikoo) to seek to reduce the total energy consumption and thus energy input of washing appliances whilst in a wash cycle by heating the first water to be used in the washing cycle using, for example an electrical resistance heater, and once that water has been used to clean the items to be washed and is ready to be discarded, seeking to transfer heat energy from that first water to clean water that will be used to either rinse the items being washed, or to perform a second wash on those items.

An alternative known approach to minimising the energy input for washing appliances is to seek to improve the efficiency of the conversion of an energy source, for example gas in EP1681006A2 (Premark), into heat energy in the water the washing apparatus is to use.

According to the present invention, there is provided a washing appliance comprising a dedicated reservoir for the washing appliance, the reservoir having an inlet to receive water and an outlet to enable flow of water therefrom, and at least one heat exchange means characterised in that at least one heat exchange means is adapted and configured to allow the transfer of ambient energy into the reservoir.

In particularly preferred embodiments of the present invention the or a heat exchange is adapted to transfer ambient energy in the form of heat in the atmosphere within or around the washing appliance, light energy and in particular sunlight, and/or waste heat energy generated by any component in the washing appliance, for example any electric motor, or by a nearby appliance such as a refrigerator or a tumble dryer.

In preferred embodiments of the present invention there are provided at least two heat exchange means each adapted to transfer heat or energy from different sources into the reservoir.

The construction of the washing appliance according to the present invention has the result that the water that is to be used in a wash cycle is not drawn straight from the water supply but has sat in the reservoir for a period before being used in a wash cycle. This has the advantage that the temperature of the water in the reservoir can be raised slowly by input of ambient heat energy without detriment to the usability of the washing appliance or the speed with which it washes once a user has inserted the items to be washed and started the wash cycle. The use of such a slow heat energy input has the effect that heat/energy sources which are either free to the user (for example ambient temperature on a warm day, or sunlight—both of which are also sustainable sources) or which are available as a result of other activities (for example the ambient temperature which results from central heating in a house or the waste heat from an electric motor) can be used to replace the requirement in known washing appliances to use electricity or gas to heat the water to a sufficient temperature for washing. This has the benefit of both being sustainable, and reducing costs to a user.

In a particularly preferred embodiment of the present invention, the heat exchange means is comprised of a heat pump of known kind. One kind of known heat pump comprises a closed circuit around which a refrigerant flows including an evaporation zone in which the refrigerant absorbs heat energy and a condensation zone in which the refrigerant releases heat energy. When this kind of pump is used, the condensation zone is within the reservoir or in thermal contact with a wall of the reservoir. The heat pump is in one embodiment so configured that the evaporation zone may be located remotely from the washing appliance in a suitable location to harvest waste heat energy, for example adjacent the cooling grill of a refrigerator or above a domestic boiler.

In a preferred washing appliance according to the present invention the appliance further comprises a heating element which may be activated to heat water passing from the reservoir to be used in a wash cycle if the temperature of the water has not been raised sufficiently by the heat exchange means.

In the context of the present invention and description thereof, it is to be understood that heating and warming up are terms describing the adding of heat energy to water, and do not indicate any particular temperature rise either in relative terms or bringing that water to an absolute temperature.

In an alternative embodiment of the invention, heat exchange between the ambient atmosphere and the reservoir may occur simply by virtue of any temperature gradient between the ambient atmosphere surrounding the reservoir and water inside the reservoir. In such an embodiment, the transfer of heat energy from the ambient atmosphere to the water may be facilitated by one or more of a variety of means. Such means may include manufacture of the reservoir from an efficiently heat conductive material, configuring the walls of the reservoir to have a large surface area both inside and outside the reservoir, mounting suitably configured heat sinks, perhaps in the form of fins of a suitable material such as aluminium on both inside and outside faces of the reservoir, and or incorporation heat conductive elements in the structure of one or maor walls of the reservoir so that one face of the element is in contact with the ambient atmosphere and one face water inside the reservoir.

In an alternative preferred embodiment of the present invention, a heat exchange means may comprise an energy conversion means, for example a photo voltaic cell, and a small heater located in the reservoir connected by electrical wires. In this embodiment the photo voltaic cell can be arranged to seat on, for example, a window to maximise the energy it gathers.

In a preferred embodiment of a washing appliance according to the present invention, there are provided at least two heat exchange means and at least one heat exchange means comprises an inlet or input arranged to receive an energy-conveying medium which carries waste heat energy from an energy-emitting apparatus and an outlet arranged to release the energy-conveying medium once heat has been extracted therefrom. It will therefore be appreciated that waste heat energy may be transferred from other appliances or heat sources, such as a tumble drier, a dishwasher, the waste bath or shower water, or any other appliance or source that emits waste heat energy. The energy-conveying medium may be a liquid, such as, for example, in the case of a waste bath water or waste water from the washing appliance, or alternatively may be a gas such as in the case of hot air emitted from a dishwasher outlet during the drying cycle.

The heat exchange means of such an embodiment of the present invention preferably comprises a channel arranged to direct the energy-conveying medium into or adjacent to the reservoir. The channel is beneficially arranged to pass through the reservoir. In a simplified embodiment, the heat exchange means is merely a wall of the reservoir. However, it will be appreciated that significantly more complex arrangements may be provided in order to ensure the maximum effectiveness or efficiency of the heat exchange. The aim is to maximise the surface area between the wall of the channel which conveys the energy-conveying medium and that of water in the reservoir. A minimal resistance to flow is preferred. In one embodiment, the channel is arranged to pass through the reservoir. In an alternative embodiment, the reservoir is shaped and configured to extend into the channel for conveying the energy-conveying medium.

The heat exchange means may be arranged to transfer heat from a remote heat source to water in the reservoir. Such a remote heat source could, for example, as described above, be another appliance. The heat energy is beneficially transferred from the remote heat source to water in the reservoir. The remote heat source may be a white goods appliance. Alternatively, the heat exchange means may be arranged to transfer heat from a source internal of the washing appliance to water in the reservoir. In such an embodiment, the heat exchange means may extend between a motor case and the reservoir, or may transfer heat energy from the waste water of the washing appliance to water in the reservoir.

In one embodiment according to the present invention, the reservoir may be arranged and configured to act as a ballast to the washing appliance. The reservoir may be located within the casing of the washing appliance or, alternatively, may be attached in some way to the appliance to have the effect of acting as a ballast. The use of the reservoir as a ballast is particularly important when the appliance according to the present invention is a laundry appliance such as a washing machine.

The present invention extends to a water supply system for a washing appliance comprising:

-   -   a reservoir having an inlet to receive water and an outlet to         enable flow of water therefrom for use in the appliance;     -   a heat exchange means configured to enable heat transfer to         water in the reservoir.

The present invention also extends to a method of preheating water for a washing appliance comprising the steps of:

-   -   providing a reservoir having an inlet to receive water and an         outlet to enable flow of water therefrom for use in the         appliance;     -   providing a heat exchange means to enable heat transfer to water         in the reservoir;     -   substantially re-filling the reservoir with water, when or         shortly after water has been transferred to the washing         appliance for use in the washing cycle.

It will be appreciated that the reservoir should either be re-filled as soon as possible after use of the water in order that there is maximum time to heat the water ready for subsequent use, or that the reservoir is so configured that when water is drawn out of the reservoir via the outlet therein, water enters the reservoir from a water supply via the inlet. In a particularly preferred embodiment of the present invention the reservoir includes one or more internal baffles or flow regulation or flow directing devices to ensure that the flow path between the inlet and outlet of the reservoir is circuitous.

The method may also comprise the step of directing a flow of energy-conveying medium to the reservoir from an appliance.

The heat exchange means may be integral or remote from the appliance and the energy-conveying medium may be a liquid or a gas.

The washing apparatus according to the present invention may further comprise a control means to enable the apparatus to monitor the temperature of water in the reservoir, such that when the temperature reaches a predetermined temperature, the wash cycle starts. This provides the benefit that a wash is started only when a predetermined quantity of energy has been transferred to the water in the reservoir, eliminating or reducing the requirement for extra heating. This control means or a second control means may be provided to link at least two appliances, such as a tumble dryer/dishwasher/washing machine. This is arranged to act intelligently to ensure waste heat generated by one appliance is transferred to a second appliance.

In a particularly preferred embodiment of the present invention, the washing appliance in which the apparatus of the present invention is employed is a laundry apparatus comprising an outer casing with a base, at least one side wall, and a top, within which are located a receptacle for items to be laundered, a means for agitation of said items and control means; in which the receptacle is a drum with a curved side wall and first and second end walls, a side wall of the outer casing is provided with a port through which an end portion of the drum may reversibly travel between a first withdrawn position and a second extended position, the distance of travel of the drum out of the side wall to the extended position being sufficient to allow access to at least one aperture in the curved side wall of the drum that is substantially parallel to the direction of travel of the drum, said aperture is configured and dimensioned to allow insertion and removal of the items to be laundered, and the direction of travel of the drum is substantially parallel to the longitudinal axis of the drum.

In one version of this preferred embodiment, the laundry apparatus further comprises a liquid retention means at least partially surrounding the receptacle and the liquid retention means is provided with a port through which an end portion of the drum may reversibly travel between a first withdrawn position and a second extended position, that port being aligned with the corresponding port in the side wall.

These and other aspects of the present invention will be apparent from, and elucidated with reference to, the embodiments described herein.

Embodiments of the present invention will now be described with reference to the accompanying drawings, in which:

FIG. 1 is a schematic diagram of a washing appliance according to an exemplary embodiment of the present invention.

FIG. 2 is a schematic diagram of a washing appliance according to a second exemplary embodiment of the present invention.

FIG. 3 is a schematic side view of a heat exchanger for use in an exemplary embodiment of the present invention.

FIG. 4 is a schematic side view of a reservoir and motor of a washing appliance according to an exemplary embodiment of the present invention.

Referring to FIG. 1, a washing apparatus 2 (generally referred to hereafter in this embodiment as a washing machine although it will be appreciated that the apparatus may equally be an alternative washing apparatus that uses heated water, such as a dishwasher) has a drum 4 for washing laundry and a reservoir 6 located proximal to the washing machine 2. The reservoir 6 is arranged to receive and retain water ready for a subsequent washing cycle of the washing machine 2. Water in the reservoir 6 may, in its simplest form, be heated by the ambient temperature when the walls of the reservoir 6 act as a heat exchanger. In an alternative embodiment, however, as described in FIG. 1, there is a heat exchange means 10 having an inlet for receiving a fluid flow, such as liquid or gas from one or more of a solar panel or collector 9, a second appliance, such as a tumble dryer, fridge, dishwasher or bath 11, and/or thirdly a means to receive waste energy from the motor 13 of the washing machine 2. These arrangements have been numbered 9, 11 and 13 respectively. In use, water, either partially or fully, is pumped out of the reservoir 6 and into the drum and used in the washing sequence. The quantity that is used for the wash sequence is automatically replenished to the reservoir after the wash fill has taken place. The reservoir is therefore always full before the next washing sequence takes place and accordingly there is provided the advantage of increasing the temperature from natural heat exchange from the ambient to the water within the reservoir. It is envisaged that a ten degree rise in temperature is likely or at least possible. The longer the water lies in the reservoir between washes, the closer to ambient temperature will be the temperature in the reservoir. In addition, a heat exchange means 10 may be beneficially provided which is arranged to receive energy from, for example, a solar panel 9, the outlet of an appliance such as a dishwasher 11, or the heat energy from the motor 13 of the washing machine 2.

Referring specifically to the appliance, such as the dishwasher 11, waste hot air from the drying cycle of the dishwasher or the waste warm water from the dishwasher is transferred through conduit 15 and through inlet 12 into the heat exchange means 10. As the waste water passes through the conduit 15, heat transfer takes place with the water in the reservoir and the waste gas or liquid passes from the heat exchange means 10 through outlet 17. Heat energy is therefore transferred to the liquid within the reservoir 6. Numerous embodiments of the heat exchange means 10 are envisaged. In the simplest embodiment, the heat exchange means is simply the wall of the reservoir 6 and the warm waste water or gas from, for example, the dishwasher passes across the wall of the reservoir and through the outlet 17, thereby having a heating effect of the water within the reservoir 6. More complex arrangements are envisaged, such as a conduit extending into the reservoir through which the warm water or gas passes, as described in more detail below.

The aim of a heat exchanger is to maximise the surface area between the wall of the flowing gas or warm fluid and the water in the reservoir. Resistance to flow should be minimised. Alternative heat exchangers are envisaged, such as a plate heat exchanger which comprises a plurality of thin slightly separated plates having a very large surface area and fluid flow passage for heat transfer through which the gas or warm waste liquid can pass. It would be appreciated by a person skilled in the art that numerous alternative embodiments of heat exchanges suitable for heating the liquid in the reservoir can be envisaged.

In the embodiments as described with respect to FIG. 1, a separate reservoir 6 is provided which may therefore be retrofit to appliances, such as dishwashers or washing machines that presently heat water for use. This reservoir could be provided to fit within, adjacent to or remote from, the washing appliance.

Referring to FIG. 2, there is a simplified exemplary embodiment of the present invention comprising a washing machine 2 having a drum 4 for washing laundry and a reservoir 6, the tank 6 being arranged to additionally act as ballasting means for the washing machine, which may be provided with one or more interconnecting hollow containers of a strong, light material (not shown). The reservoir in the embodiment as indicated in FIG. 2 acts as a ballast to a washing machine thereby assisting in stabilisation during rotation of the drum which especially occurs at high speeds or when the load is out of balance. The water ballast may be, in addition to or in place of, a traditional steel or concrete ballast. The ballast reservoir 6 is filled on installation and this water, either partially or fully, is pumped out into the drum and used in the washing sequence. This quantity of water is then automatically replenished to the reservoir 6 once the wash fill has taken place. The reservoir 6 is therefore always full before the washing sequence takes place to give maximum stability and also enables the maximum temperature rise to occur. This water ballast (in reservoir 6) can negate the requirement for steel or concrete ballasts. Additionally, there is also provided a heating means (not shown) which may be provided in or adjacent to reservoir 6 which is arranged to heat cold water for use during a wash cycle. There is also provided a channel 8 enabling fluid flow between the reservoir 6 and drum 4. There is further provided a heat exchanger 10 which is arranged and configured to be in fluid communication with the reservoir 6 and arranged to enable heat transfer between a remote apparatus and the water within the reservoir 6. The heat exchanger 10 comprises an inlet 12. The inlet 12 may be connected to any apparatus, and the present invention is not limited in this regard. For example, it is envisaged that suitable apparatus may be a bath, an air-conditioning unit, a tumble dryer etc. Such apparatus are commonly found in a home and, as such, may easily be linked to the heat exchanger 10. However, the invention is also not limited to this environment and may also be used on a commercial basis.

In its simplest form, hot waste water from the wash cycle may be channelled through inlet 12 to heat exchanger 10. Eventually, this heated bath water will flow directly into the drainage system. However, if this water flows to the heat exchanger and thereby conducts heat energy to water in the reservoir 6, some of the heat energy that otherwise would be wasted is extracted from the waste flow. Once the heat energy has been extracted, the waste water is then allowed to either flow to the drain or, alternatively, may be filtered and cleaned for other purposes. Alternatively, if the waste energy received from the other apparatus is in the form of hot vapour from a tumble dryer, heat may be extracted from this vapour in the same way.

In one embodiment of the present invention, the laundry apparatus may be controlled such that laundry is placed in the drum 4 and, when the water within the reservoir 6 has reached sufficient temperature, the laundry apparatus may start automatically. This would provide a significant energy benefit over prior art arrangements, as significant energy must be used to heat the water for washing the laundry.

The above embodiment of the present invention has been described in simple terms only. However, it is envisaged that there are numerous alternative arrangements possible without departing from the scope of the appended claims. A second embodiment of the present invention may remove the requirement for the reservoir 6 and simply enable heat exchange between the cold water inlet to the drum 4 and waste energy from another appliance. It will be appreciated, however, that such a system is not as efficient as defined above by utilising a reservoir 6.

Referring to FIG. 3, there is a heat exchanger according to an exemplary embodiment of the first aspect of the present invention shown schematically. The heat exchanger is arranged to extend between a motor of the laundry appliance and the reservoir for holding the water for use in the washing appliance. The heat exchanger may be constructed of any suitable heat conducting material, such as a metal and, beneficially, an aluminium alloy. In certain embodiments, the heat exchanger may be a solid piece of metal, or alternatively may comprise a fluid therein for effective heat transfer. In one embodiment, it is envisaged that the water in the reservoir may access into the heat exchanger and flow to the motor casing for effective heat transfer. Alternatively, the heat exchanger can be arranged such that the exchanger extends between the motor and the water inlet into the laundry appliance. it will be appreciated, however, that the heating effects associated with heating water in a reservoir is likely to be more effective than heating water as it flows from a mains tap to the appliance. Referring to FIG. 3, there is generally designated the heat exchanger 20 having a first end 22 arranged to communicate with a motor (not shown) such that the maximum amount of heat energy is extracted from the motor as it runs. The heat exchanger 20 may be connected to the motor by any means including screw type mechanisms or a conductive adhesive material 24, for example. The heat exchanger 20 further comprises a neck portion 26 arranged to extend through an aperture located through a wall of a reservoir which may be arranged to act as a ballast for the appliance. In an alternative embodiment, the neck portion 26 may not extend through the wall of the reservoir. Rather, the second portion 28 of the heat exchanger may simply contact the outer wall of the reservoir. However, in a preferred embodiment, the second portion 28 extends into the reservoir and comprises a plurality of protrusions thereon arranged to conduct the greatest possible amount of heat energy to the water in the reservoir. It will be appreciated that any number of heat exchangers may be used as necessary to act to transfer the greatest degree of heat energy available from the motor.

Referring to FIG. 4, an exemplary embodiment of part of a laundry appliance is schematically shown including the motor 40 and tank 6. The motor 40 is arranged to power the action of the drum 4 during the wash cycle. The heat exchangers 20 as schematically shown and arranged to provide a heat sink for transferring the heat energy from the motor into the first portion 22, through the neck portion 26 and into the second portion 28 in which water is located such that heat energy can be conducted from a second portion 28 to the water, thereby raising the associated temperature.

It will be appreciated that any number of heat exchangers can be utilised in order to obtain the greatest amount of heat energy from the motor during operations.

Major advantages are envisaged for the present invention, as are numerous implementations of this concept. It should be noted that the above-mentioned embodiments illustrate rather than limit the invention, and those skilled in the art will be capable of designing many alternative embodiments without departing from the scope of the invention as defined in the appended claims. Additionally, it will be appreciated that features of each aspect of the invention and embodiments of each aspect can be interchanged and/or added to other aspects/embodiments. 

1. A washing appliance comprising a dedicated reservoir for the washing appliance, the reservoir having an inlet to allow inflow of water and an outlet to enable outflow of water, and at least one heat exchanger to transfer ambient energy outside the reservoir into the reservoir.
 2. An appliance according to claim 1 in which at least one heat exchanger comprises an energy converter.
 3. An appliance according to claim 2 in which the converter means comprises a photo voltaic cell.
 4. An appliance according to claim 1 in which at least one heat exchanger comprises an inlet arranged to receive a flow of energy-conveying medium from an energy-emitting apparatus remote from the appliance, and an outlet arranged to release the flow of energy-conveying medium once heat energy has transferred into the reservoir.
 5. An appliance according to claim 1 in which at least one heat exchanger is arranged to transfer heat energy from a source internal of the washing appliance to the water in the reservoir.
 6. An appliance according to claim 5 which further comprises a motor and in which at least one heat exchanger is arranged and configured to transfer heat energy generated by operation of the motor into the reservoir.
 7. An appliance according to claim 1 in which the reservoir is arranged and configured to act as a ballast to the washing appliance.
 8. An appliance according to claim 1 in which the appliance further comprises an outer casing with a base, at least one side wall, and a top, within which are located a receptacle for items to be laundered, and an agitator of said items; in which the receptacle is a drum with a curved side wall and first and second end walls, a side wall is provided with a port through which an end portion of the drum may reversibly travel between a first withdrawn position and a second extended position, the distance of travel of the drum out of the side wall to the extended position being sufficient to allow access to at least one aperture in the curved side wall of the drum that is substantially parallel to the direction of travel of the drum, said aperture is configured and dimensioned to allow insertion and removal of the items to be laundered, and the direction of travel of the drum is substantially parallel to the longitudinal axis of the drum.
 9. An appliance according to claim 1 in which the laundry apparatus further comprises a retainer means at least partially surrounding a receptacle for items to be laundered and the liquid receptacle is provided with a port through which an end portion of a drum may reversibly travel between a first withdrawn position and a second extended position, that port being aligned with the corresponding port in a side wall.
 10. A water supply system for a washing appliance comprising: a reservoir having an inlet to receive water and an outlet to enable flow of water therefrom for use in the appliance; a heat exchanger configured to enable heat transfer of ambient energy outside the reservoir to water in the reservoir.
 11. A method of pre-heating water for a washing appliance comprising the steps of: providing a reservoir having an inlet to received water therefrom for use in the appliance; providing a heat exchanger to enable heat transfer of ambient energy outside the reservoir to water in the reservoir; substantially filling the reservoir with water at the same time as or shortly after water has been transferred to the washing appliance for use in the washing cycle. 